Genus Pione Gray, 1867

Synonymy. Cliona of various authors, e.g. for some species in Hancock (1849). Archaeoclina Czerniavsky, 1878. Papilissa von Lendenfeld, 1888. Gapoda Laubenfels, 1936 .

Diagnosis. Excavating sponges in alpha and beta morphology. Delicate, commonly straight tylostyles as megascleres, microspined (rarely smooth) oxeas and microspined rhabds as microscleres. Microrhabds straight or helical, forming ectosomal crusts (adapted from Rützler 2002).